1. FIELD
This invention is in the field of toy vehicles, and particularly relates to self-powered miniature toy vehicles capable of negotiating in water as well as on very steep and irregular surfaces.
2. PRIOR ART
An amphibious toy vehicle offered at one time by the Eldon Company had the capability of operation on rough surfaces or in water. This vehicle was driven by a battery-powered mechanism and had a separate screw drive for propulsion in water. The screw was fixed in its driving direction relative to the vehicle chassis.
Many water-play toys have been made to resemble boats or water creatures and to propel themselves along the surface of a body of water. Some of these toys depended for propulsion (but not to any significant extent for flotation) upon rotating wheels or other rotating elements rotatably fixed to the sides of the toys. For example, the Tomy Company has offered bathtub toys configured as toy penguins, fish, dolphins, frogs, and so forth, which float and whose limbs rotate to propel them. The same company has offered bathtub toys configured as toy paddlewheel boats, with lateral, rotatably fixed propulsive paddlewheels.
These toys are all made for water use exclusively, rather than for amphibious use. In the case of the paddlewheel toys, it does not appear that the paddlewheels would both at the same time touch a surface on which the toys were placed, and, even if they would, neither the paddlewheels nor the toy bodies generally were suitably configured to provide good traction or effective operation over rough surfaces. In the case of the rotating-limb toys, the dynamic visual effect of such toys operating on a dry surface would be to lurch forward erratically, producing--at best--generally a comic or silly impression.
All of these tub toys may well be adequate for their intended purposes. They would not be suitable for a toy amphibious vehicle that is intended to suggest the operation of a real amphibious vehicle--e.g., a swamp buggy or a military amphibious carrier. Such a real vehicle should operate very tenaciously and effectively over rough surfaces as well as operate in water, to produce an exciting, "adventure" kind of impression rather than one that is comic or silly.